4 boneless, skinless chicken breasts (about 2 pounds), trimmed of fat and gristle
1 cup buttermilk
1-1/2 cups panko breadcrumbs
3/4 cup freshly grated Grana Padano
1 teaspoon dried oregano, preferably Sicilian, on the branch
2 tablespoons chopped fresh parsley
2 tablespoons chopped fresh basil, plus 1/4 cup leaves, and whole sprigs for garnish
5 tablespoons extra-virgin olive oil
2 cups prepared fresh tomato sauce
4 slices low-moisture mozzarella
4 roasted cherry tomatoes (optional, for garnish)
Season the chicken breasts with salt, and place them in a resealable plastic bag. Pour in the butter-milk, and marinate in the refrigerator for two hours.
Drain the chicken, and preheat the oven to 400 degrees.
Line a baking sheet with parchment paper. In a medium bowl, toss together the panko, grated Grana Padano, dried oregano, chopped parsley, chopped basil, three tablespoons of the olive oil, and 1/2 teaspoon salt. Stir to incorporate everything fully into the crumbs.
Put the drained chicken breasts in the bowl with the seasoned breadcrumbs one at a time, and pat well on both sides so the crumbs cover the chicken on all sides. Set the breaded chicken breasts on the parchment paper, arranged so they don’t touch each other.
Bake the chicken until the coating is crisp and browned and the chicken is just cooked through, about 15 minutes. While the chicken bakes, combine the tomato sauce, the remaining two tablespoons olive oil, and 1/4 cup basil leaves in a blender, and purée until smooth. Season with salt. Pour the purée into a small saucepan, and warm it over low heat.
When the chicken is just cooked through, top with the sliced mozzarella and bake until the cheese is just melted, about two minutes. Spread the tomato emulsion on plates, top with the chicken and a roasted cherry tomato, if using, and serve.